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Modified stochastic user-equilibrium assignment algorithm for urban rail transit under network operation

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Journal of Central South University 2013年第10期20卷 2897-2904页

作者：朱炜胡昊徐瑞华洪玲 Center of Transportation Research School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong University School of Transportation Engineering Tongji University

Based on the framework of method of successive averages(MSA), a modified stochastic user-equilibrium assignment algorithm was proposed, which can be used to calculate the passenger flow distribution of urban rail transit(URT) under network operation. In order to describe the congestion's impact to passengers' route choices, a generalized cost function with in-vehicle congestion was set up. Building on the k-th shortest path algorithm, a method for generating choice set with time constraint was embedded, considering the characteristics of network operation. A simple but efficient route choice model, which was derived from travel surveys for URT passengers in China, was introduced to perform the stochastic network loading at each iteration in the algorithm. Initial tests on the URT network in Shanghai City show that the methodology, with rational calculation time, promises to compute more precisely the passenger flow distribution of URT under network operation, compared with those practical algorithms used in today's China.

关键词： urban rail transit stochastic user equilibrium assignment algorithm method of successive averages network operation

Equilibrium model and algorithm of urban transit assignment based on augmented network

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Science China(Technological Sciences) 2009年第11期52卷 3158-3167页

作者： SI BingFeng ZHONG Ming SUN HuiJun GAO ZiYou Institute of System Science School of Traffic and TransportationBeijing Jiaotong UniversityBeijing 100044China Department of Civil Engineering University of New BrunswickFrederictonN.B.E3B 5A3Canada

The passenger flow assignment problem for the urban transit network is relatively complicated due to the complexity of the network structure and many factors influencing the passengers' route and line choices. In the past three decades, many models have been proposed to solve the passenger flow assignment problem. However, the common-line problem remains challenging in transit flow assignment. In this paper, the characteristics of the urban transit network is analysed and a new technique of augmented network is proposed to represent the urban transit system. The purpose is to eliminate the complex common-line problem when modeling transit passenger flow assignment. Through this augmentation technique, the urban transit system can be represented by an augmented network-it then behaves like a simple network and can be used as a generalized network for traffic assignment or network analysis. This paper presents a user equilibrium model for the urban transit assignment problem based on such a technique. A numerical example is also provided to illustrate the approach.

关键词： transit network flow assignment user equilibrium algorithm

Functional Analysis of Three Rice Chloroplast transit Peptides

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Rice science 2019年第1期26卷 11-20页

作者： HE Lei CHEN Guang ZHANG Sen QIU Zhennan HU Jiang ZENG Dali ZHANG Guangheng DONG Guojun GAO Zhenyu REN Deyong SHEN Lan GUO Longbiao QIAN Qian ZHU Li State Key Laboratory of Rice Biology China National Rice Research Institute

Chloroplast transit peptides(CTPs) can be used to transport non-chloroplastic proteins into the chloroplasts. Here, we studied the CTPs of three rice(Oryza sativa L.) chloroplast-localized proteins and found that their CTPs could be used to transport non-chloroplast-localized proteins into the chloroplasts. Fusion proteins lacking the CTP remained located in the cytoplasm. Furthermore, we constructed green fluorescent protein fusion vectors with the three CTPs and three non-chloroplast-localized proteins, Ghd10, MULTI-FLORET SPIKELET1(MFS1), and SHORTENED UPPERMOST INTERNODE 1(SUI1). After transforming these constructs into rice protoplasts, the fusion proteins all localized in the chloroplasts. Collectively, our results showed that these CTPs can transport non-chloroplast-localized proteins into the chloroplasts, and more importantly, these CTPs can be applied to engineer chloroplast metabolism.

关键词： rice chloroplast transit peptide translocated function subcellular location

A tentative study for the prediction of the CME related geomagnetic storm intensity and its transit time

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Science China(Technological Sciences) 2005年第6期48卷 648-668页

作者： ZHAO Xinhua1,2 & FENG Xueshang1,3 1. SIGMA Weather Group, Key Laboratory of Space Weather, Center for Space Science and Applied Re-search, Chinese Academy of Sciences, Beijing 100080, China 2. Graduate School of the Chinese Academy of Sciences, Beijing 100039, China 3. School of Geophysics and Geoinformation Systems, China University of Geosciences, Beijing 100083, China 1. SIGMA Weather Group Key Laboratory of Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences 100080 Beijing China 2. Graduate School of the Chinese Academy of Sciences 100039 Beijing China 3. School of Geophysics and Geoinformation Systems China University of Geosciences 100083 Beijing China

Using 80 CME-ICME events during 1997.1―2002.9, based on the eruptive source locations of CMEs and solar magnetic field observation at the photosphere, a current sheet magnetic coordinate (CMC) system is established in order to study the propagation of CME and its geoeffectiveness. In context of this coordinate system, the effect of the eruptive source location and the form of heliospheric current sheet (HCS) at the eruptive time of CME on the geomagnetic storm intensity caused by CME and the CME’s transit time at the Earth is investigated in detail. Our preliminary conclusions are: 1) The geomagnetic disturbances caused by CMEs tend to have the so-called “same side-opposite side effect”, i.e. CMEs erupt from the same side of the HCS as the earth would be more likely to arrive at the earth and the geomagnetic disturbances associated with them tend to be of larger magnitude, while CMEs erupting from the opposite side would arrive at the earth with less probability and the corresponding geomagnetic disturbance magnitudes would be relatively weaker. 2) The angular separation between the earth and the HCS affect the corresponding disturbance intensity. That is, when our earth is located near the HCS, adverse space weather events occur most probably. 3) The erupting location of the CME and its nearby form of HCS will also affect its arrival time at the earth. According to these conclusions, in this context of CMC coordinate we arrive at new prediction method for estimating the geomagnetic storm intensity (Dstmin) caused by CMEs and their transit times. The application of the empirical model for 80 CME-ICME events shows that the relative error of Dst is within 30% for 59% events with Dstmin≤?50 nT, while the averaged absolute error of transit time is lower than 10 h for all events.

关键词： coronal mass ejections, current sheet magnetic coordinate system, geomagnetic storm intensity, transit time, prediction method.

Contemporary meta-analysis of short-term probiotic consumption on gastrointestinal transit

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World Journal of Gastroenterology 2016年第21期22卷 5122-5131页

作者： Larry E Miller Angela K Zimmermann Arthur C Ouwehand Miller Scientific Consulting Inc. Asheville NC 28803 United States DuPont Nutrition and Health FIN-02460 Kantvik Finland

AIM: To determine the efficacy of probiotic supplementation on intestinal transit time(ITT) in adults and to identify factors that influence these outcomes. METHODS: We conducted a systematic review of randomized controlled trials of probiotic supplementation that measured ITT in adults. Study quality was assessed using the Jadad scale. A random effects meta-analysis was performed with standardized mean difference(SMD) of ITT between probiotic and control groups as the primary outcome. Meta-regression and subgroup analyses examined the impact of moderator variables on SMD of ***: A total of 15 clinical trials with 17 treatment effects representing 675 subjects were included in this analysis. Probiotic supplementation was moderately efficacious in decreasing ITT compared to control, with an SMD of 0.38(95%CI: 0.23-0.53, P < 0.001). Subgroup analyses demonstrated statistically greater reductions in ITT with probiotics in subjects with vs without constipation(SMD: 0.57 vs 0.22, P < 0.01) and in studies with high vs low study quality(SMD: 0.45 vs 0.00, P = 0.01). Constipation(R^2 = 38%, P < 0.01), higher study quality(R^2 = 31%, P = 0.01), older age(R^2 = 27%, P = 0.02), higher percentage of female subjects(R^2 = 26%, P = 0.02), and fewer probiotic strains(R^2 = 20%, P < 0.05) were predictive of decreased ITT with probiotics in meta-regression. Medium to large treatment effects were identified with B. lactis HN019(SMD: 0.67, P < 0.001) and B. lactis DN-173 010(SMD: 0.54, P < 0.01) while other probiotic strains yielded negligible reductions in ITT relative to ***: Probiotic supplementation is moderately efficacious for reducing ITT in adults. Probiotics were most efficacious in constipated subjects, when evaluated in high-quality studies, and with certain probiotic strains.

关键词： Constipation Gastrointestinal Intestinal transit time Meta-analysis Probiotics

Effect of thienorphine on intestinal transit and isolated guinea-pig ileum contraction

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World Journal of Gastroenterology 2013年第9期19卷 1444-1450页

作者： Pei-Lan Zhou Yu-Lei Li Ling-Di Yan Zheng Yong Gang Yu Hua-Jin Dong Hui Yan Rui-Bin Su Ze-Hui Gong Beijing Institute of Pharmacology and Toxicology

AIM: To evaluate the effect of thienorphine on small intestinal transit in vivo and on guinea-pig ileum (GPI) contraction in vitro . METHODS: The effects of thienorphine on intestinal transit were examined in mice and in isolated GPI. Buprenorphine and morphine served as controls. The distance traveled by the head of the charchol and the total length of the intestine were measured in vivo . Gastrointestinal transit was expressed as a percentage of the distance traveled by the head of the marker relative to the total length of the small intestine. The isolated GPI preparations were connected to an isotonic force transducer and equilibrated for at least 1 h before exposure to drugs. Acetylcholine was used for muscle stimulation. RESULTS: Thienorphine (0.005-1.0 mg/kg, ig ) or bu-prenorphine (0.005-1.0 mg/kg, sc ) dose-dependently significantly inhibited gut transit compared with saline. Thienorphine inhibited gut transit less than buprenorphine. The maximum inhibition by thienorphine on the intestinal transit was 50%-60%, whereas the maximum inhibition by morphine on gut transit was about 100%. Thienorphine also exhibited less inhibition on acetylcholine-induced contraction of GPI, with a maximum inhibition of 65%, compared with 93% inhibition by buprenorphine and 100% inhibition by morphine. Thienorphine induced a concentration-dependent decrease in the basal tonus of spontaneous movement of the GPI, the effect of which was weaker than that with buprenorphine. The duration of the effect of thienorphine on the GPI was longer than that with buprenorphine. CONCLUSION: Thienorphine had less influence, but a longer duration of action on GPI contraction and moderately inhibited intestinal transit.

关键词： Thienorphine Buprenorphine Guinea-pig ileum Gut transit Contraction

Probiotic supplementation decreases intestinal transit time: Meta-analysis of randomized controlled trials

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World Journal of Gastroenterology 2013年第29期19卷 4718-4725页

作者： Larry E Miller Arthur C Ouwehand Miller Scientific Consulting Inc. Arden NC 28704 United States DuPont Nutrition and Health FIN-02460 Kantvik Finland

AIM: To determine the efficacy of probiotic supplementation on intestinal transit time (ITT) and to identify factors that influence these outcomes. METHODS: A systematic review of randomized controlled trials (RCTs) of probiotic supplementation that measured ITT in adults was conducted by searching MEDLINE and EMBASE using relevant combinations. Main search limits included RCTs of probiotic supplementation in healthy or constipated adults that measured ITT. Study quality was assessed using the Jadad scale. A random effects meta-analysis was performed with standardized mean difference (SMD) of ITT between probiotic and control groups as the primary outcome. Meta-regression and subgroup analyses were conducted to examine the impact of moderator variables on ITT SMD. RESULTS: A total of 11 clinical trials with 13 treatment effects representing 464 subjects were included in this analysis. Probiotic supplementation was associated with decreased ITT in relation to controls, with an SMD of 0.40 (95%CI: 0.20-0.59, P < 0.001). Constipation (r 2 = 39%, P = 0.01), higher mean age (r 2 = 27%, P = 0.03), and higher percentage of female subjects (r 2 = 23%, P < 0.05) were predictive of decreased ITT with probiotics in meta-regression. Subgroup analyses demonstrated statistically greater reductions in ITT with probiotics in subjects with vs without constipation and in older vs younger subjects [both SMD: 0.59 (95%CI: 0.39-0.79) vs 0.17 (95%CI: -0.08-0.42), P = 0.01]. Medium to large treatment effects were identified with Bifidobacterium Lactis (B. lactis ) HN019 (SMD: 0.72, 95%CI: 0.27-1.18, P < 0.01) and B. lactis DN-173 010 (SMD: 0.54, 95%CI: 0.15-0.94, P < 0.01) while other single strains and combination products yielded small treatment effects. CONCLUSION: Overall, short-term probiotic supplementation decreases ITT with consistently greater treatment effects identified in constipated or older adults and with certain probiotic strains.

关键词： Constipation Gastrointestinal Intestinal transit time Meta-analysis Probiotics

Colon transit time according to physical activity and characteristics in South Korean adults

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World Journal of Gastroenterology 2013年第4期19卷 550-555页

作者： Kang Ok Cho Yun Ju Jo Bong Kil Song Jung Woo Oh Yeon Soo Kim Institute of Korea Exercise and Development Seoul 151-877South Korea Y Department of Internal Medicine Eulji Universitiy School of MedicineSeoul 139-711South Korea Health and Exercise Science Laboratory Institute of Sports ScienceSeoul National UniversitySeoul 151-742South Korea

AIM:To investigate factors contributing to the colon transit time(CTT),physical activity and characteristics were ***:Forty-seven Korean adults(males,n=23;females,n=24) took a capsule containing 20 radioopaque markers to measure the *** subjects used an accelerometer to measure the physical activity and underwent a bioelectrical impedance analysis to determine the physical ***-nutrient was also ***:The mean total CTTs(TCTT) in the males and females were 8.8 and 24.7 h(P=0.002),*** the male subjects,the right CTT(3.5±4.9 h vs 10.0±11.6 h,P=0.023) and recto-sigmoid CTT(4.4±4.7 vs 13.6±12.5 h,P=0.004) were significantly shorter and the total energy expenditure(637.6±44.3 kcal vs 464.3±64.9 kcal,P=0.003),total activity count(247 017±75 022 count vs 178 014±75 998 count,P=0.003),energy expenditure of light intensity(148.5±6.9 kcal vs 120.0±16.8 kcal,P=0.006),energy expenditure of moderate intensity(472.0±36.2 kcal vs 281.4±22.2 kcal,P < 0.001),fat intake(65.5±23.3 g vs 51.2±17.4 g,P=0.010),and water consumption(1714.3±329.4 g vs 1164.7±263.6 g,P=0.009) were significantly higher than in the female *** correlations,when adjusted for gender,fiber(r =-0.545,P < 0.001) and water intake(r =-0.257,P < 0.05) correlated significantly with the TCTT in all *** addition,the body mass index(r =-0.424,P < 0.05) and fiber intake(r =-0.417,P < 0.05) in the males as well as the fiber intake(r =-0.655,P < 0.001) in the females showed significant correlations with the ***:The subjects showed significant gender differences in the TCTT,right CTT,and recto-sigmoid ***,the intake of the fiber and water contributed to the CTT.

关键词： Colon transit time Physical activity Characteristics Macro-nutrient South Korean

Subtotal colonic bypass plus colostomy with antiperistaltic cecoproctostomy for the treatment of slow transit constipation in an aged population:A retrospective control study

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World Journal of Gastroenterology 2018年第23期24卷 2491-2500页

作者： Yang Yang Yong-Li Cao Wen-Hang Wang Yuan-Yao Zhang Nan Zhao Dong Wei Institute of Anal-Colorectal Surgery No.150 Central Hospital of PLA

AIM To compare the efficacy,improved quality of life,and prognosis in patients undergoing either subtotal colonic bypass with antiperistaltic cecoproctostomy(SCBAC) or subtotal colonic bypass plus colostomy with antiperistaltic cecoproctostomy(SCBCAC) for the treatment of slow transit *** Between October 2010 and October 2014,aged patients with slow transit constipation who were hospitalized and underwent laparoscopic surgery in our institute weredivided into two groups: the bypass group,15 patients underwent SCBAC,and the bypass plus colostomy group,14 patients underwent SCBCAC. The following preoperative and postoperative clinical data were collected: gender,age,body mass index,operative time,first flatus time,length of hospital stay,bowel movements(BMs),Wexner fecal incontinence scale,Wexner constipation scale(WCS),gastrointestinal quality of life index(GIQLI),numerical rating scale for pain intensity(NRS),abdominal bloating score(ABS),and ClavienDindo classification of surgical complications(CD) before surgery and at 3,6,12,and 24 mo after *** All patients successfully underwent laparoscopic surgery without open surgery conversion or surgeryrelated death. The operative time and blood loss were significantly less in the bypass group than in the bypass plus colostomy group(P = 0.007). No significant differences were observed in first flatus time,length of hospital stay,or complications with CD > 1 between the two groups. No patients had fecal incontinence after surgery. At 3,6,and 12 mo after surgery,the number of BMs was significantly less in the bypass plus colostomy group than in the bypass group. The parameters at 3,6,12,and 24 mo after surgery in both groups significantly improved compared with the preoperative conditions(P < 0.05),except NRS at 3,6 mo after surgery in both groups,ABS at 12,24 mo after surgery and NRS at 12,24 mo after surgery in the bypass group. WCS,GIQLI,NRS,and ABS significantly improved in the bypass plus col

关键词： Subtotal colonic bypass plus colostomy with antiperistaltic cecoproctostomy Subtotal colonic bypass with antiperistaltic cecoproctostomy Minimally invasive surgery for treatment of constipation Clinical efficacy Slow transit constipation in an aged population